Clamshell bucket and corner bracket therefor



June 6, 1939. G. J. EHRHARDT 2,161,147

CLAMSHELL BUC JKET AND CORNER BRACKET THEREFOR I Filed Jan 25, 1939ZSheets-Sheet 1 INVENTOR George J. Ehrhard'f June 6, 1939- G. J.EHRHARDT CL-AMSHEL-L BUCKET AND comma BRACKET THEREFOR Filed Jan. 25, 1939 2 Sheets-Sheet 2 INVENTOR 27 George J. Ehrhardf Patented June 6,1939 '1 UNITED. STATES CLAMSHELL BUCKET ANDIYYVCORNER '7BRACKETTHEREFOR.

George J. Ehrhardt, Oakmont, Pa., assignor t Blaw-Knox Company,Pittsburgh; Pa., a corporation of New Jersey Application January 25,1939,]Serial No. 252,780

10 Claims.

This invention relatesv to a clamshell bucket and a corner brackettherefor. The field in which clamshell buckets are used has been greatlybroadened in recent years. Originally clamshell ,buckets were simplyused for moving loose material, but they have more recently come intowide use for excavating and digging, which requires a strongerconstruction and a more powerful closing action.

The construction of the clamshell bucket corner brackets and the mannerof attachment thereof to the bucket is of great importance in thedesigning and building of clamshell bucket structures, as the bucketmembers or scoops are 15;; operated by corner bars which are connectedtherewith through the corner brackets. Consequently the thrust of thecorner bars is transmitted to the bucket through the corner brackets andthe structure of the corner brackets and the 20 manner of cooperationthereof with the bucket are of considerable consequence.

When clamshell buckets were used only for moving loose material it wasthecustomary practice to position the corner brackets inside the bucketcorners and rivet them to the sides of the bucket. This practice wascontinued when clamshell buckets came to be used for heavier work, butthe bracket extensions to which the corner rods are connected were madelonger and extended entirely outside the back of the bucket to affordgreater leverage in operation. This construction was not fullysatisfactory as it required making the corner brackets of relativelymassive construction, considerably increasing their cost, and alsorequired much firmer connections between the corner brackets and thebucket, which further added to the cost of the structure as a whole.strengthening of the corner brackets and their 4' connections with thebucket a tendency existed to tear the corner brackets 01f of the sidesof the bucket when the open bucket was dropped upon a relatively hardsurface such as might be encountered in excavating in rock strata or inre- 45; moving old pavements. The rivets connecting the corner bracketsto the bucket sides were called upon to sustain the entire shockoccasioned upon dropping of the bucket and repeated such shocks resultedin loosening of the rivets and consequent misalignment and bending ofthe structure.

Thereafter corner brackets extending inside the bucket but having a lippassing over the edge of the bucket and down the outside of the back ofthe bucket came into use in an effort to obviate the disadvantages ofthe earlier corner bracket structure above referred to. However, thesemodified corner brackets were likewise found to be far fromsatisfactory. It was found practically impossible to make a proper fitbe- 60. tween the inside and outside portions of the Moreover, it wasfound that despite the bracket and the back of the bucket withoutmachining, which, of course, could not be resorted. to on account ofcost. The fit was almost always either too loose or too tight. If it wastoo loose the rivets would soon loosen with a result similar to thatabove described in the case of the earlier structure. If the fit was tootight difficulties were encountered in assembly with a consequentincrease in manufacturing cost, and it was difficult to properly alignthe bearings in the bracket extensions and in the corner bars and toinsert the pivot pins therein, which bearings and pivot pins had ofcourse to be'machined before attachment of the corner brackets to thebucket.

Ihave devised a corner 'bracket'structure for clamshell bucketsobviating all of the disadvantages above mentioned which have beeninherent in corner brackets'heretofore employed, and a clamshell bucketstructure embodying my improved corner brackets is found ,to haveimportant advantagesin operation. I provide a corner bracket forclamshell buckets which comprises three generally plate-like portionswhich are preferably integrally connected together so as to form astructure similar to a corner of a box adapted to be placed over anupper corner ofthe bucket so that two of such portions lie against the.outside of thebucket and may be connected respectively with the back andside of the bucket and the third of such portions overlies the upperedge of the bucket, the bracket havingan extension for connection with acorner bar for operating the bucket integrally connected Withvsaidstructure. I prefer to cast the bracket as a single integralcasting,..although the parts thereof may be joined together, as, forexample, by welding. In any event, my bracket preferably has acontinuous generally L-shaped body having a first portion adapted to lieagainst the outside of and be connected with the back of the bucket anda second portion adapted to lie against the outside of and be connectedwith the side of the bucket. The top portion of the bracket which isconnected with both of said first and second portions acts as a bracingmember and makes the bracket as 'a whole very strong and rigid. Thefirst and second portions above mentioned lie against the outside of thebucket at the corner and ach is directly connected with the bucket,preferably by rivets. The bracket extension for connection with a cornerbar for operating the bucket is preferably integrally connected withboth of the back and top portions of the bracket. The extensionpreferably extends outwardly from the outside of the backrof the bucketand has means for connection with the corner bar positioned so that suchconnection is effected entirely outside the back of the bucket. Byreason of the strength and. rigidity of the bracket the extension forconnection with the corner bar the bucket is open the thrust of thecorner bars is such as to press the brackets directly against thecorners of the bucket so that there is no tendency to tear the bracketsaway or to loosen their connection with the bucket corners. In myimproved structure there is no overhanging lip on the corner bracket andno problem of fitting tbe corner bracket over the edge of the bucket. Aclamshell bucket equipped with my improved corner brackets is adaptedfor hard digging without any of the disadvantages encountered with theprior structures.

Other details, objects and advantages of the invention will becomeapparent as the following description of a present preferred embodimentthereof proceeds.

In the accompanying drawings I have shown a present preferred embodimentof the invention, in which:

Figure 1 is a side view of a clamshell bucket embodying my invention,the bucket being shown in closed position in full lines and in openposition in dot and dash lines;

Figure 2 is a fragmentary view to enlarged scale of a corner of thebucket showing one form of my improved corner bracket in top plan view;

Figure 3 is a further fragmentary view of the same corner of the bucketshowing the bracket in side view; and

Figure 4 is a further fragmentary view of the same corner of the bucketshowing the bracket as viewed from the back of the bucket.

Referring now more particularly to the drawings, there is shown aclamshell bucket structure designated generally by reference numeral 2.The general structure of the bucket and its operating mechanism may beof any well known form such, for example, as disclosed in Patent No.1,686,176. As the bucket operating means forms no part of the presentinvention only the bucket per se and the lower ends of the corner barsare shown in the drawings, it being understood that suitable supportingand operating mechanism will be employed.

The bucket comprises opposed bucket members or scoops 3 which may be ofknown construction each having opposed sides 4, the upper portions ofwhich are constituted by portions of a bent plate 5. The plate 5 of eachscoop is of generally U shape and forms the upper portion of both thesides and the back of the scoop in the structure shown in the drawings.The back of each scoop below the portion of the bent plate 5 disposed atthe back of the scoop is designated by reference numeral 6 and mergesinto the bottom 7. Each scoop is provided with a digging edge havingteeth 8, the teeth of the respective scoops being staggered so that theyinterfit when the bucket is closed as shown in Figure 1. Each scoop hasan extension 8' and a pivot pin 9 passes through both such extensions aswell known in the art. The bucket operating mechanism, most of which isnot shown, may be conventional.

Connected with each of the two upper corners of each of the two scoops 3is a corner bracket designated generally by reference numeral 9. Thecorner bracket structure isshown in detail in Figures 2, 3 and 4. Eachof such brackets comprises a first or back portion II] which liesagainst the outside of and is connected with the back of the bucket, asecond or Side P X Q l H of the bucket at the corner thereof.

which lies against the outside of and is connected with the side of thebucket, and a top portion l2 which is integrally connected with both ofthe portions ii] and H and overlies the upper edge l3 The respectivebracket portions i and I l are connected with the bucket by rivets M.

The bracket has an extension i which at its outer extremity isbifurcated to provide opposed bearing portions IS, the extension beingpreferably integrally connected with both of the portions l0 and E2 ofthe bracket. As above mentioned, the bracket is preferably cast as asingle piece, although it may be otherwise formed so that the respectiveparts thereof will be solidly maintained in their relation to eachother. In the form shown in the drawings the extension I5 forms a partof a unitary casting and is joined to the portion ID of the bracketthroughout substantially the entire height of such portion and is alsojoined to the top E2 of the bracket as shown at II. The opposed bearingportions it of the bracket i5 are drilled and machined for the receptionof a pin l8 connecting the corner bracket with one of the corner bars i9whose lower extremity is likewise drilled and machined and lies betweenthe bearing portions i6 and also receives the pin H8. The extension l5extends outwardly from the outside of the back of the bucket so that thepin connection between the bracket and the corner bar lies entirelyoutside the back of the bucket, as shown in Figures 1 and 3.

No part of my improved corner bracket as shown extends within thebucket. By reason of the rigid connection of the side and back portionsof the bracket to the side and back of the bucket and the connection ofsuch side and back portions of the bracket by the top portion I2 thereofa very strong and rigid structure is provided. No interfitting of thebracket and any portion of the bucket is required, the bracket simplybeing laid over the corner of the bucket and the side and back portionsof the bracket being riveted to the side and back portions of thebucket, respectively. When the open bucket is dropped on a hard surfacethe brackets arethrust cornerwise directly against the upwardlypresented corners of the bucket scoops so that there is no tendency totear away or disengage the brackets but only to more tightly engage themagainst the corners of the bucket. The brackets may be accuratelyadjusted in position in relation to the bucket so that the pinconnections with the corner bars may be properly aligned.

As above mentioned, the strength and rigidity of the bracket structureand its relation to the bucket makes it feasible to substantiallyincrease the length of the extension i5 so that greater leverage andgripping power is afforded in closing of the bucket. My clamshell bucketstructure as a whole is far better adapted for heavy work than anyclamshell bucket structure heretofore available with which I amfamiliar.

While I have shown and described a present preferred embodiment of theinvention, it is to be distinctly understood that the same is notlimited thereto but may be otherwise variously embodied within the scopeof the following claims.

I claim:

1. A corner bracket for a clamshell bucket, comprising a first portionadapted to lie against the outside of and be connected with the back ofthe bucket, a second portion adapted to lie against the outside of andbe connected with the side of the bucket, a top portion integrallyconnected with both of said first and second portions adapted to overliethe upper edge of the bucket, and an extension for connection with acorner bar for operating the bucket integrally connected with both of.said first and top portions.

2. A corner bracket for a clamshell bucket, comprising a continuousgenerally L-shaped body having a first portion adapted to lie againstthe outside of and be connected with the back of the bucket and a secondportion adapted to lie against the outside of and be connected with theside of the bucket, a top portion integrally connected with both of saidfirst and second portions adapted to overlie the upper edge of thebucket, and an extension for connection with a corner bar for operatingthe bucket integrally connected with both of said first and topportions.

3. A corner bracket for a clamshell bucket, comprising a first portionadapted to lie against the outside of and be connected with the back ofthe bucket, a second portion adapted to lie against the outside of andbe connected with the side of the bucket a top portion integrallyconnected with both of said first and second portions adapted tooverlie'the upper edge of the bucket, and an extension for connectionwith a corner bar for operating the bucket integrally connected withboth of said first and top portions and extending outwardly from theoutside of the back of the bucket and having means for connection withthe corner bar positioned so that such connection is effected entirelyoutside the back of the bucket.

4. A corner bracket for a clamshell bucket, comprising a first portionadapted to lie against the outside of and be connected with the back ofthe bucket, a second portion adapted to lie against the outside of andbe connected with the side of the bucket, a top portion connecting saidfirst and second portions adapted to overlie the upper edge of thebucket, and an extension for connection with a corner bar for operatingthe bucket integrally connected with said first portion and extendingoutwardly from the outside of the back of the bucket and having meansfor connection with the corner bar positioned so that such connection iseffected entirely outside of and substantially spaced from the back ofthe bucket.

5. A corner bracket for a clamshell bucket, comprising three generallyplate-like portions integrally connected together so as to form astructure similar to a corner of a box adapted to be placed over anupper corner of the bucket so that two of said portions lie against theoutside of the bucket and may be connected respectively with the backand side of the bucket and the third of said portions overlies the upperedge of the bucket, and an extension for connection with a corner barfor operating the bucket integrally connected with said structure.

6. A corner bracket for a clamshell bucket, comprising three generallyplate-like portions integrally connected together so as to form astructure similar to a corner of a box adapted to be placed over anupper corner of. the bucket so that two of said portions lie against theoutside of the bucket and may be connected respectively with the backand side of the bucket and the third of said portions overlies the upperedge of the bucket, and an extension for connection with a corner barfor operating the bucket integrally connected with two of said threegenerally platelike portions.

7. A corner bracket for a clamshell bucket, comprising three generallyplate-like portions integrally connected together so as to form astructure similar to a corner of a box adapted to be placed over anupper corner of the bucket so that two of said portions lie against theoutside of the bucket and may be connected respectively with the backand side of the bucket and the third of said portions overlies the upperedge of the bucket, and an extension for connection with a corner barfor operating the bucket integrally connected with said structure andextending outwardly from the outside of the back of the bucket andhaving means for connection with the corner bar positioned so that suchconnection is effected entirely outside the back of the bucket.

8. A clamshell bucket structure comprising opposed openable and closablebucket members, corner brackets on the upper corners of said bucketmembers, each of said brackets comprising a first portion lying againstthe outside of and connected with the back of. the bucket member towhich it is attached, a second portion lying against the outside of andconnected with the side of such bucket member, a top portion connectingsaid first and second portions overlying the upper edge of such bucketmember and an extension for connection with a corner bar for operatingthe bucket integrally connected with the bucket, and operating means forthe bucket including corner bars connected with the respective bracketextensions.

9. A clamshell bucket structure comprising opposed openable and closablebucket members, corner brackets on the upper corners of said bucketmembers, each of said brackets comprising three generally plate-likeportions integrally connected together so as to form a structure similarto a corner of a box and positioned with two of said plate-like portionslying against the outside of the bucket member to which it is attachedand connected respectively with the back and side of such bucket memberand with the third of such portions overlying the upper edge of suchbucket member and an extension for connection with a corner bar foroperating the bucket integrally connected with said bracket structure,and operating means for the bucket including corner bars connected withthe respective bracket extensions.

10. A clamshell bucket structure comprising opposed openable andclosable bucket members, corner brackets on the upper corners of saidbucket members, each of said brackets comprising a first portion lyingagainst the outside of. and connected with the back of the bucket memberto which it is attached, a second portion lying against the outside ofand connected with the side of such bucket member, a top portionconnecting said first and second portions overlying the upper edge ofsuch bucket member and an extension for connection with a corner bar foroperating the bucket integrally connected with the bracket, andoperating means for the bucket including corner bars connected with therespective bracket extensions, the connections between the respectivecorner bars and bracket extensions lying entirely outside the back ofthe bucket.

GEORGE J EHRHARDT.

. CERTIFICATE OF CORRECTION. Patent No. 2,161,1Lfi. June 6, 1959.

GEORGE J. EHRHARDT.

It is hereby certified that error appears in the printed specificationof the above numbered patent requiring correction as follows: Page 5,second column, line 51+, claim 8, for "bucket" first occurrence, readbracket; and that the said. Letters Patent should be read with thiscorrection therein that the same may conform to the record of the casein the Patent Office.

Signed and sealed this Lgth' day of July, A, D. 1959a Henry Van Arsdale(Seal) Acting Commissioner of Patents.

